Quantification of Dental Fluorosis Using Fluorescence Imaging

Abstract

Fluorescence imaging hardware and software have been recently employed to assess demineralization due to early dental caries. Dental fluorosis also presents as diffuse surface hypomineralization of enamel and in principle similar measurement methods might be applicable to both. The caries analysis system requires the user to select an area of sound enamel around the lesion so that the affected surface can be reconstructed and the lesion subtracted. Whereas early caries presents as discrete isolated lesions fluorosis is characterized by diffuse opacities covering most of the tooth. Consequently it is difficult to use commercial QLF software for the assessment of fluorosis, as there is typically no sound area of enamel to use for reconstruction. This study describes a fluorescent imaging device capable of recording digital images of the anterior teeth and also software that is able to objectively measure fluorosis area and severity. A convenience sample of 26 subjects with a range of fluorosis from TF scores 0–3 took part in the study. The upper left central incisor of these subjects was scored for fluorosis using the TF index, photographed using a conventional digital camera and imaged using the fluorescence imaging device. The TF index was then used to visually score the digital photographs and the fluorescence images. The data from the fluorescence method demonstrated a strong correlation with TF scores from fluorescence images (Kendall’s tau = 0.862). The fluorescence imaging method shows promise as an objective, potentially blinded system for the longitudinal assessment of enamel fluorosis in vivo.

Clinical Studies of Dental Erosion and Erosive Wear

“…QLF is a non-invasive optical technique initially developed for in vivo measurement of early caries [de Josselin de Jong et al, 1995] and since used extensively for investigation of caries and to a lesser extent fluorosis [Pretty et al, 2006].…”

Longitudinal Analyses of Early Lesions by Fluorescence

“…However, there are few reports of longitudinal studies with QLF that follow caries lesions longer than 6 mos (Ferreira Zandoná et al, 2000, 2003aKambara et al, 2003;Karlsson et al, 2007;Mattousch et al, 2007;van der Veen et al, 2007). The interpretation of QLF images without the aid of visual examinations is challenged by confounding effects, as previously reported (Pretty et al, 2006). To avoid this issue, we have proposed to combine the use of QLF with a visual criterion (ICDAS), to benefit from the high sensitivity of the QLF and high specificity of the visual method (Ferreira Zandoná et al, 2010).…”

“…Because this method is quantitative (Ando et al, 2001;Karlsson et al, 2007;Kühnisch et al, 2007), it allows for longitudinal monitoring of lesion progression (Ferreira Zandoná et al, 2000;Tranaeus et al, 2001;Kambara et al, 2003). The combined use of ICDAS with QLF (Ferreira Zandoná et al, 2010) allows for the earlier detection of caries lesions, avoiding the pitfalls that have been associated with QLF: the confounding effects of developmental defects, fluorosis (Pretty et al, 2006), stain (Shi et al, 2001), swollen gingival margin, presence of plaque, and quality of fluorescence images (Heinrich-Weltzien et al, 2005).…”

Quantitative Light Fluorescence (QLF) and Polarized White Light (PWL) assessments of dental fluorosis in an epidemiological setting

“…These can be taken during examinations and graded remotely, thus enabling the examiners to be blinded [17]. However, there is a lack of research looking at how such images can be standardized, their quality optimized (especially with regard to specular reflections caused by ring flashes) and their analysis recorded [18]. Collecting images as part of epidemiological studies has additional benefits including archiving, the ability to assess longitudinal changes, scoring by multiple examiners, remote examiner scoring and producing training sets for examiner calibration.…”